Wire drawing device and method for manufacturing wire

ABSTRACT

Included are a wire supply part, a wire pulling part, a first capstan mechanism part and a second capstan mechanism part. The first capstan mechanism part includes a plurality of first capstans, a first rotation drive source and a first rotation transmission mechanism part that transmits the rotation drive force of the first rotation drive source to the respective first capstans, and the second capstan mechanism part includes a plurality of second capstans and a plurality of second rotation drive sources that rotatively drive the respective second capstans in an individually manner. Dies are provided between ones of the respective first capstans and the respective second capstans.

TECHNICAL FIELD

The present invention relates to the technology of drawing a wire.

BACKGROUND ART

The conventional technologies of drawing wires are disclosed in PatentDocument 1 and Patent Document 2.

In Patent Document 1, a plurality of intermediate drawing capstans aredivided into two or more blocks such that some of them are accommodatedin one block, and the plurality of intermediate drawing capstans aredriven by one motor per block.

In Patent Document 2, a plurality of wire drawing units including adrive capstan and a capstan drive motor are disposed between unwindingmeans and winding means.

In the wire drawing machines as described above, the degree of diameterreducing deformation is set correspondingly to the intervals between thecapstans, which are configured such that a wire is gradually subjectedto diameter reducing deformation through a plurality of diameterreducing deformation processes. Specifically, dies are disposed betweenthe capstans correspondingly to the degree of diameter reducingdeformation. Further, the drawing speed ratio of capstans disposed so asto sandwich each die is set correspondingly to the degree of diameterreducing deformation by the die.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Application Laid-Open No. 11-47821(1999)

Patent Document 2: Japanese Patent Application Laid-Open No. 2005-103623

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

In the case of drawing a wire, it is necessary to appropriately set orchange the degree of diameter reducing deformation of a wire inaccordance with a material of a base wire to be processed, a targetfinished wire diameter or the like.

In the technology disclosed in Patent Document 1, however, a pluralityof intermediate drawing capstans are rotatively driven by one drivemotor per block, which makes it difficult to change the setting of thedegree of diameter reducing deformation of a wire.

Meanwhile, in the technology disclosed in Patent Document 2, allcapstans are rotatively driven by a motor in an individual manner, whichcomplicates maintenance tasks.

Therefore, an object of the present invention enables easy response to,for example, adjustment or change of the degree of diameter reducingdeformation of a wire in accordance with a material of a base wire, atarget finished wire diameter or the like while simplifying maintenancetasks.

Means to Solve the Problems

In order to solve the above-mentioned problems, a first aspect relatesto a wire drawing machine drawing a wire, which includes: a wire supplypart supplying a wire; a wire pulling part pulling the wire; a firstcapstan mechanism part provided between the wire supply part and thewire pulling part on a side closer to the wire supply part, whichincludes a plurality of first capstans, a first rotation drive source,and a first rotation transmission mechanism part transmitting a rotationdrive force of the first rotation drive source to the plurality of firstcapstans; a second capstan mechanism part provided between the wiresupply part and the wire pulling part on a side closer to the wirepulling part than the first capstan mechanism part, which includes aplurality of second capstans, and a plurality of second rotation drivesources rotatively driving the plurality of second capstans in anindividual manner; and a plurality of dies disposed between ones of theplurality of first capstans and the plurality of second capstans.

According to a second aspect, in the wire drawing machine according tothe first aspect, drawing speed ratios between adjacent ones of theplurality of second capstans are set so that a wire that has passedthrough all of the plurality of second capstans has a smallest finishedwire diameter among a plurality of types of finished wire diameters tobe manufactured and that a wire that has passed through part of theplurality of second capstans has one finished wire diameter among theplurality of types of finished wire diameters to be manufactured.

According to a third aspect, in the wire drawing machine according tothe first or second aspect, drawing speed ratios between adjacent onesof the plurality of second capstans are set so as to gradually decreasetoward the wire pulling part.

According to a fourth aspect, in the wire drawing machine according toany one of the first to third aspects, a wire subjected to a wiredrawing process is an aluminum wire or an aluminum alloy wire, anddrawing speed ratios between ones of the plurality of first capstans areset so that the wire whose diameter has been reduced to 0.5 mm orsmaller is subjected to the wire drawing process while the wire is drawnby the second capstan.

According to a fifth aspect, the wire drawing machine according to anyone of the first to fourth aspects further includes a finishing capstanmechanism part provided between the wire supply part and the wirepulling part on a side closer to the wire pulling part than the secondcapstan mechanism part, which includes at least one finishing capstan, afinishing rotation drive source, and a finishing transmission mechanismpart transmitting a rotation drive force of the finishing rotation drivesource to the finishing capstan.

A sixth aspect relates to a strand manufacturing method of manufacturinga strand by drawing a wire with a wire drawing machine including: a wiresupply part supplying a wire; a wire pulling part pulling the wire; afirst capstan mechanism part provided between the wire supply part andthe wire pulling part on a side closer to the wire supply part, whichincludes a plurality of first capstans, a first rotation drive source,and a first rotation transmission mechanism part transmitting a rotationdrive force of the first rotation drive source to the plurality of firstcapstans; a second capstan mechanism part provided between the wiresupply part and the wire pulling part on a side closer to the wirepulling part, which includes a plurality of second capstans, and aplurality of second rotation drive sources rotatively driving theplurality of second capstans in an individual manner; and a plurality ofdies disposed between ones of the plurality of first capstans and theplurality of second capstans, the method including: setting rotationalspeeds of the plurality of second capstans so that a wire that haspassed through all of the plurality of second capstans has a smallestfinished wire diameter among a plurality of types of finished wirediameters to be manufactured and that a wire that has passed throughpart of the plurality of second capstans has one finished wire diameteramong the plurality of types of finished wire diameters to bemanufactured; and changing targets of the plurality of second capstansthrough which the wire passes to all or part thereof, to therebymanufacture strands having the plurality of types of finished wirediameters.

Effects of the Invention

According to the wire drawing machine of the first aspect, in the firstcapstan mechanism, the rotation drive force of one first rotation drivesource is transmitted to a plurality of first capstans via the firstrotation transmission mechanism part, which simplifies maintenancetasks. In the second capstan mechanism, the rotational speeds of aplurality of second rotation drive sources are individually adjusted soas to change the rotational speeds of the plurality of second capstans,which changes the drawing speed ratios between adjacent ones of therespective second capstans. This enables an easy response to adjustmentor change of the degree of diameter reducing deformation of a wire inaccordance with the material of a base wire, a target finished wirediameter or the like.

According to the second aspect, strands having a small diameter can bemanufactured by performing the wire drawing process with all of theplurality of second capstans. Further, wire drawing performed by part ofa plurality of second capstans enables to manufacture a strand havingone of a plurality of types of finished wire diameters to bemanufactured. Accordingly, once the drawing speed ratios betweenadjacent ones of the second capstans are set, the strands having aplurality of types of finished wire diameters can be easily manufacturedwithout changing the setting.

According to the third aspect, the drawing speed ratios between adjacentones become smaller as the diameter of the wire becomes smaller, whichprevents cutting of the wire more reliably.

Generally, an aluminum wire or aluminum alloy wire is difficult to cutwhen having a diameter larger than 0.50 mm and is easy to cut whenhaving a diameter smaller than 0.50 mm in the wire drawing process.Therefore, as in the fourth aspect, the wire drawing process isperformed by the first capstan mechanism part to an extent that thediameter is reduced to approximately 0.50 mm, which enables efficientwire drawing at a fixed delivery speed ratio. Meanwhile, a wire whosediameter has been reduced to 0.50 mm or smaller is subjected to the wiredrawing process by drawing of the second capstans, which enables thewire drawing process in which the drawing speeds are adjusted so as tomake it difficult to cut an aluminum wire or aluminum alloy wire.

According to the fifth aspect, the wire drawing process is performed ata relatively large degree of diameter reducing deformation by the firstcapstan mechanism part, and the wire drawing process is performed at adegree of diameter reducing deformation that is adjusted in accordancewith a material or the like by the second capstan mechanism part, whichenables the wire drawing process at a degree of diameter reducingdeformation suitable for finishing by a plurality of finishing capstans.

According to the sixth aspect, the strands having a plurality of typesof finished wire diameters can be easily manufactured without changingthe rotational speeds of the second capstans.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic plan view showing a wire drawing machine accordingto an embodiment.

FIG. 2 is a schematic side view showing the wire drawing machine.

FIG. 3 is a figure showing examples of setting of percentage of areareduction.

FIG. 4 is a figure showing spots at which a wire is broken and factorsof breaking.

FIG. 5 is an explanatory view showing an example of performing a wiredrawing process with the use of part of second capstans.

FIG. 6 is a schematic plan view showing a wire drawing machine accordingto a modification.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, a wire drawing machine and a strand manufacturing methodaccording to an embodiment are described. FIG. 1 is a schematic planview showing a wire drawing machine 20 according to the embodiment, andFIG. 2 is a schematic side view showing the wire drawing machine 20.

The wire drawing machine 20 is an apparatus that draws a wire so as toreduce diameters of wires 10, and includes a wire supply part 22, a wirepulling part 26, a first capstan mechanism part 30, a second capstanmechanism part 40 and a plurality of dies 60. Note that the wires 10generally refer to all wires including those before, after and during awire drawing process, and in some cases, discrimination is made suchthat ones before the process are base wires 10 a and drawn ones afterthe process are strands 10 b. The strands 10 b are used as, for example,cores of electric wires in a single manner or in a twisted manner.

The wire supply part 22 is configured so as to supply the base wires 10a. More specifically, the wire supply part 22 is configured toaccommodate the base wires 10 a that are wound around a reel-likemember. The wire supply part 22 is rotatively supported on the upstreamside of a predetermined wire drawing process line L such that the basewires 10 a can be drawn from this wire supply part 22.

The wire pulling part 26 is configured so as to pull the strands 10 b.More specifically, in the wire pulling part 26, a reel-like membercapable of accommodating the strands 10 b in a wound manner is supportedto be rotatively driven by a rotation drive source such as a motor. Thewire pulling part 26 is disposed on the downstream side of the wiredrawing process line L such that the strands 10 b processed to have afinished wire diameter are pulled by and accommodated in this wirepulling part 26.

In the present embodiment, a plurality of (in this case, seven) wiresupply parts 22 and a plurality of (in this case, seven) wire pullingparts 26 are provided so that a plurality of (in this case, seven) basewires 10 a can be subjected to the wire drawing process. Needless tosay, a twisting mechanism part that twists a plurality of strands 10 bmay be provided on the downstream side of the second capstan mechanismpart 40. In this case, only one wire pulling part that pulls only onetwisted wire may be provided.

The first capstan mechanism part 30 is provided between the wire supplypart 22 and the wire puling part 26 on the side closer to the wiresupply part 22, and includes a plurality of (in this case, eight) firstcapstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8), one firstrotation drive source 34 and a first rotation transmission mechanismpart 36.

Each of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8)is formed approximately in a disc shape or cylindrical shape, and acircumferential groove around which the wire 10 can be wound is formedon an outer circumference thereof. The circumferential grooves areformed in accordance with the number of wires 10 to be processed, and inthis case, seven circumferential grooves are formed. The respectivefirst capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) are disposedso as to be lined at intervals along the wire drawing process line Lfrom the upstream side toward the downstream side and supported so as torotate about the rotation axis approximately in a horizontal directionalmost perpendicular to the wire drawing process line L. The respectivefirst capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) arerotatively driven in the state in which the wires 10 are wound aroundthe circumferential grooves of the respective first capstans 32(1),32(2), . . . , 32(6), 32(7) and 32(8), so that the wires 10 are drawn atthe drawing speed corresponding to the rotational speed.

Note that the rotation axis of each of the first capstans 32(1), 32(2),. . . , 32(6), 32(7) and 32(8) may be an axis along an approximatelyperpendicular direction or a direction oblique to the approximatelyperpendicular direction.

The first rotation drive source 34 is a motor such as an AC motor and isconfigured so as to generate a rotation drive force.

The first rotation transmission mechanism part 36 is configured so as totransmit the rotation drive force of the one first rotation drive source34 to the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7)and 32(8). More specifically, the first rotation transmission mechanismpart 36 includes drive shafts 36 a that are respectively connected tothe first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) andspeed change mechanisms 36 b that change and transmit the speed of arotation movement between the drive shafts 36 a and so on. The speedchange mechanism 36 b is composed of various mechanisms such as aplurality of gears, a pulley and a transmission belt wound around thepulley, and is configured to transmit the rotation movement at apredetermined speed change ratio by appropriating setting a geardiameter, the number of teeth of the gear, a pulley diameter or thelike. In this case, the rotation movement of the first rotation drivesource 34 is transmitted to the first capstan 32(8) on the downstreamside at the rotational speed without change, and is transmitted from thedownstream side to the first capstans 32(7), 32(6), . . . , 32(2) and32(1) on the upstream side at a gradually increasing speed. Accordingly,the rotational speeds of the first capstans 32(1), 32(2), . . . , 32(6),32(7) and 32(8) have values determined in accordance with the rotationalspeed of the first rotation drive source 34, and the rotational speedratio of the respective first capstans 32(1), 32(2), . . . , 32(6),32(7) and 32(8) is constant between ones of the upstream side anddownstream side of the wire drawing process line L (in some case, simplyreferred to as between adjacent ones). In the present embodiment,description is given assuming that the respective capstans have the samediameter, and thus the constant rotational speed ratio between beforeadjacent ones means the constant drawing speed ratio between adjacentones. In this case, in the respective first capstans 32(1), 32(2), . . ., 32(6), 32(7) and 32(8), the drawing speed ratios between adjacent onesthereof are set to be a given fixed value. A more specific settingexample of the drawing speed ratio is described below.

The second capstan mechanism part 40 includes a plurality of (in thiscase, seven) second capstans 42(9), 42(10), . . . , 42(13), 42(14) and42(15) and a plurality of second rotation drive sources 44, and isprovided between the wire supply part 22 and the wire puling part 26 onthe side closer to the wire pulling part 26 than the first capstanmechanism part 30. The second capstan 42(15) on the most downstream sideof the wire supply line among the second capstans 42(9), 42(10), . . . ,42(13), 42(14) and 42(15) is referred to as a finishing capstan in somecases.

Similarly to the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and32(8), each of the second capstans 42(9), 42(10), . . . , 42(13), 42(14)and 42(15) is formed approximately in a disc shape or cylindrical shape,and a circumferential groove around which the wire 10 can be wound isformed on an outer circumference thereof. The respective second capstans42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are rotatively disposedand supported so as to be lined at intervals along the wire drawingprocess line L from the upstream side toward the downstream side in thisorder. The second capstans 42(9), 42(10), . . . , 42(13), 42(14) and42(15) are rotatively driven in the state in which the wires 10 arewound around the circumferential grooves of the second capstans 42(9),42(10), . . . , 42(13), 42(14) and 42(15), so that the wires 10 aredrawn at the drawing speed corresponding to the rotational speed.

The second rotation drive source 44 is a motor capable of adjusting arotational speed, such as an AC motor, and a plurality of (in this case,six) second rotation drive sources 44 are provided correspondingly tothe respective second capstans 42(9), 42 (10), . . . , 42(13), 42(14)and 42(15). The respective second rotation drive sources 44 areindividually connected to the second capstans 42(9), 42(10), . . . ,42(13), 42(14) and 42(15), and the respective second rotation drivesources 44 are configured so as to rotatively drive the second capstansin an individual manner. Accordingly, the rotational speeds of thesecond capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) havevalues determined in accordance with the rotational speeds of therespective second rotation drive sources 44, and the rotational speedratios between adjacent ones of the respective second capstans 42(9),42(10), . . . , 42(13), 42(14) and 42(15) can be adjusted by theadjustment of the rotational speeds of the respective second rotationdrive sources 44. In the present embodiment, description is givenassuming that the respective capstans have the same diameter, and thusthe fact that the rotational speed ration between adjacent ones can beadjusted means that the drawing speed ratio between adjacent ones can beadjusted. In this case, the drawing speed ratios between adjacent onesof the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14)and 42(15) are set so as to gradually decrease from the upstream sidetoward the downstream side of the wire drawing process line L (that is,are set such that the speed difference gradually decreases). A specificadjustment setting example of each drawing speed ratio is describedbelow.

The configuration is made so as to include the first capstan mechanismpart 30 and the second capstan mechanism part 40 as described above,with the result that the process region in which the drawing speed ratiois constant can be provided between adjacent ones of only the firstcapstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and that theprocess region in which the drawing speed ratio is variable can beprovided between adjacent ones (that is, including the relation betweenthe first capstan 32(8) and the second capstan 42(9)) of the capstansincluding the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and42(15).

Provided between the second capstan mechanism part 40 and the wirepulling part 26 is a wire speed difference absorbing mechanism part 70including a pair of rollers 72 a and 72 b. The wire speed differenceabsorbing mechanism part 70 is also referred to as, for example, aso-called dancer roller, and is configured such that the movable sideroller 72 b is supported so as to move close to and apart from the fixedroller 72 a. The distance between both rollers 72 a and 72 b is adjustedin accordance with the wire speed difference between the second capstan42(15) and the wire pulling part 26, whereby, for example, the slacknessof the wire 10 between the second capstan mechanism part 40 and the wirepulling part 26 and the action by the excessive pulling force of thewire 10 are suppressed.

A plurality of dies 60 are processing tools for processing the wire 10to have reduced diameter and deformed, and are detachably disposedbetween ones of the first capstans 32(1), 32(2), . . . , 32(6), 32(7)and 32(8) and the second capstans 42(9), 42(10), . . . , 42(13), 42(14)and 42(15). More specifically, the dies 60 are members formed of metalor the like, in which a reduced diameter processing hole for allowingthe wire 10 to pass therethrough is formed. In this case, a plurality of(in this case, seven) reduced diameter processing holes are formed in aparallel manner in accordance with the number of the wires 10 to beprocessed. The reduced diameter processing holes are formed into athrough-hole shape whose diameter subsequently decreases from theupstream side toward the downstream side along the process line L. Theaperture diameter on the upstream side of the reduced diameterprocessing hole is approximately identical to the diameter of the wire10 guided by the die 60, and the aperture diameter on the downstreamside of the diameter reduced processing hole is approximately identicalto a target diameter of one to be processed by the die 60. In a casewhere the aperture area on the upstream side and the aperture area onthe downstream side of the reduced diameter processing hole in the die60 are represented by S1 and S2, respectively, a percentage of reductionof the aperture area ((S1-S2)/S1) is referred to as a percentage of areareduction. The percentage of area reduction is set in accordance with atarget degree of diameter reducing process in the die 60. A guide holefor guiding the wire 10 to the reduced diameter processing hole may beformed on the upstream side of the reduced diameter processing hole.Note that the respective dies 60 are detachably disposed for detachment,change, maintenance or the like of the dies 60. In particular, in a casewhere the drawing speed ratio between adjacent ones is adjusted alongwith a change of the speeds of the second capstans 42(9), 42(10), . . ., 42(13), 42(14) and 42(15), it is necessary to replace the dies 60 withones having a corresponding percentage of area reduction.

The relationship between the percentage of area reduction and thedrawing speed ratio is now described. That is, when the wire 10 isprocessed to have a reduced diameter by the die 60, the wire 10 iselongated to be long. Therefore, the speed of drawing the wire 10 needsto be made larger on the downstream side of the die 60 compared with theupstream side thereof. Further, the wire 10 is elongated more as thedegree of diameter reducing process (percentage of area reduction) ofthe wire 10 by the die 60 becomes larger, and accordingly the ratio ofthe drawing speed on the downstream side to the drawing speed on theupstream side in the die 60 needs to be large. From the relationship ofthe cross-sectional area of the wire 10, for example, in a case wherethe percentage of area reduction by the die 60 is “r”, it suffices thatthe ratio of the drawing speed difference to the drawing speed on thedownstream side with the die 60 being sandwiched between the upstreamside and the downstream side (that is, (V2-V1)/V2) in the case where thedrawing speed on the upstream side is V1 and the drawing speed on thedownstream side is V2) is set to “r”. That is, when a study is made soas to perform processing in each capstan portion at a predetermineddegree of diameter reducing deformation, the percentage of areareduction in the die 60 is determined as one type in terms of design.Correspondingly to this, the drawing speed ratio between adjacentcapstans is determined as one type as well. That is, the setting andadjustment of the degree of diameter reducing deformation by each die 60are synonymous with the setting and adjustment of the percentage of areareduction by a die and the setting and adjustment of the drawing speedratio between adjacent capstans. The following description is given onthat assumption.

Further, the wire drawing machine 20 includes a control unit 68. Thecontrol unit 68 is a typical microcomputer including a CPU, ROM, RAM andthe like. The control unit 68 receives, via an input part 68 a such as aswitch, on/off commands for the first rotation drive source 34 and eachsecond rotation drive source 44 and a rotational speed command for eachsecond rotation drive source 44. Moreover, the control unit 68 controlson/off operation of the first rotation drive source 34 and each secondrotation drive source 44 in accordance with the command and controls therotational speed of each second rotation drive source 44. Alternatively,the rotational speed of each second rotation drive source 44 may beadjusted by individual setting for each second rotation drive source 44.

Hereinafter, the operation of the wire drawing machine 20 is describedwith reference to specific percentages of area reduction (%) of aluminumwire or aluminum alloy wire. FIG. 3 is a figure showing examples ofsetting of the percentage of area reduction. Here, examples in which thebase wire 10 a that is made of an aluminum alloy and has a diameter of1.100 mm is used as a base wire are assumed. In FIG. 3, the left columnshows the numbers of brackets of the first capstans 32(1), 32(2), . . ., 32(6), 32(7) and 32(8) and the second capstans 42(9), 42(10), . . . ,42(13), 42(14) and 42(15) (that is, order of capstans disposed from theupstream side toward the downstream side in the wire drawing processline L), the center column shows the diameter of the wire 10 woundaround and drawn by each capstan, and the right column shows thepercentages of area reduction by the die 60 located on the upstream sideof each capstan. As described above, the percentage of area reductionrepresents the degree of diameter reducing deformation by the die 60 andalso indirectly represents the drawing speed ratio between the adjacentcapstans with the die 60 being sandwiched therebetween.

As shown in this figure, the percentage of area reduction is set to agiven fixed value, 20% between ones of the first capstans 32(1), 32(2),. . . , 32(6), 32(7) and 32(8) in the first capstan mechanism part 30.That is, one configured to have a speed change ratio of that percentageof area reduction (drawing speed ratio) is used as the first rotationtransmission mechanism part 36. Note that the above-mentioned percentageof area reduction is a setting value that is obtained by consideringthat the wire drawing process for the wire 10 whose diameter has beenreduced to 0.5 mm or smaller can be performed while drawing the wire 10by the second capstan 42 (9). Accordingly, the base wire 10 a having adiameter of 1.10 mm is deformed to have a reduced diameter in stages,from 0.98 mm to 0.87 mm, 0.78 mm, 0.70 mm, 0.62 mm, 0.56 mm and 0.50 mm.Then, the wire 10 whose diameter has been reduced to 0.50 mm isprocessed so as to be drawn by the die 60 between the capstan 32(8) andthe capstan 42(9) while being drawn by the following second capstan42(9).

Description is now given of the reason why the wire drawing process isallowed for the wire 10 reduced to be 0.5 mm or smaller while drawingthe wire 10 by the second capstan 42(9).

FIG. 4 is a figure showing the spots in which a wire is broken in a casewhere the inventors have tried wire drawing process under variousconditions, with various aluminum alloy wires as the base wires. Thetarget wires herein include so-called 1000 series aluminum alloys (inparticular, such as 1050 to 1080), 5000 series aluminum alloys (inparticular, such as 5154 to 5454), and other aluminum alloys such asAl—Fe alloy, Al—Fe—Mg alloy and Al—Mg alloy in the JIS. As shown in thisfigure, wire breaking has occurred almost in the die portions processedin which a diameter is reduced to 0.5 mm or smaller. It is conceivablethat an increased percentage of area reduction increases a possibilitythat wire breaking may be caused by factors such as an increase ofdrawing resistance and frictional heat due to improvements in speed.Therefore, the wire drawing process in the stage in which the wire 10has a relatively large diameter is performed at the percentage of areareduction of a given fixed value by the respective first capstans 32(1),32(2), . . . , 32(6), 32(7) and 32(8) in the first capstan mechanismpart 30. On the other hand, the wire drawing process at the time whenthe wire 10 has a relatively small diameter (0.50 mm or smaller) isperformed in the drawing process by the second capstans 42(9), 42(10), .. . , 42(13), 42(14) and 42(15) capable of, for example, changingsetting of the percentage of area reduction. As a result, the wire 10can be manufactured by adjusting the percentage of area reduction so asto make it difficult to cause wire breaking.

Between adjacent ones of the respective second capstans 42(9), 42(10), .. . , 42(13), 42(14) and 42(15), the percentages of area reduction areset to be smaller than the percentages of area reduction between ones ofthe first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) in thefirst capstan mechanism part 30 and are also set to gradually decreasetoward the wire pulling part 26. That is, setting is made such that thedrawing speed ratios corresponding thereto gradually decrease toward thewire pulling part 26. To what extent the percentage of area reduction isset or at what rate the percentage of area reduction is graduallydecreased is experimentally determined in accordance with the materialof the wire 10, a target diameter thereof or the like. That is, it ispreferable to set the percentage of area reduction as large as possiblefor processing with a minimum number of dies 60. On the contrary, wirebreaking is apt to occur when the percentage of area reduction is large.Whether wire breaking is apt to occur depends on the material of a wire,a process diameter thereof or the like, and thus the percentage of areareduction is experimentally determined so as to be set as large aspossible within the range of a frequency causing no problem.

In this case, the respective percentages of area reduction are set suchthat in a case where the wire drawing process is performed via all ofthe second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15),the wire 10 has the smallest finished wire diameter among a plurality oftypes of finished wire diameters to be manufactured. Moreover, thepercentage of area reduction is set such that in a case where the wiredrawing process is performed via part of a plurality of second capstans42(9), 42(10), . . . , 42(13), 42(14) and 42(15) (that is, the wire isnot wound around the remaining capstans, and corresponding dies areomitted), the wire 10 has one finished wire diameter among a pluralityof types of finished wire diameters to be manufactured. In this case, asuitable speed command value is provided to the control unit 68 throughthe input part 68 a and the speed command value is set and stored in thecontrol unit 60 so as to obtain the above-mentioned drawing speed ratio,and the control unit 60 controls driving of the respective secondrotation drive sources 44 in accordance with the control command value.

It is assumed here that the finished wire diameters of the strands 10 bto be manufactured are 0.42 mm, 0.36 mm, 0.34 mm, 0.32 mm and 0.30 mm onthe assumption of the case where those are used as the cores of theelectric wires to be manufactured.

The percentage of area reduction between the first capstan 32(8) and thesecond capstan 42(9) is set to 16%, the percentage of area reductionbetween the second capstans 42(9) and 42(10) is set to 15%, thepercentage of area reduction between the second capstans 42(10) and42(11) is set to 14%, the percentage of area reduction between thesecond capstans 42(11) and 42(12) is set to 13%, the percentage of areareduction between the second capstans 42(12) and 42(13) is set to 12%,the percentage of area reduction between the second capstans 42(13) and42(14) is set to 11%, and the percentage of area reduction between thesecond capstans 42(14) and 42(15) is set to 10%. Then, the diameter ofthe wire 10 is 0.45 mm at the time of being drawn by the second capstan42(9), is 0.42 mm at the time of being drawn by the second capstan42(10), is 0.39 mm at the time of being drawn by the second capstan42(11), is 0.36 mm at the time of being drawn by the second capstan42(12), is 0.34 mm at the time of being drawn by the second capstan42(13), is 0.32 mm at the time of being drawn by the second capstan42(14), and is 0.30 mm at the time of being drawn by the second capstan42(15). Accordingly, the strand 10 b having the smallest diameter of0.30 mm can be obtained in the case where the wire drawing process isperformed via all of the second capstans 42(9), 42(10), . . . , 42(13),42(14) and 42(15). Alternatively, through the processes via ones up tothe second capstan 42(10), ones up to the second capstan 42(12), ones upto the second capstan 42(13), ones up to the second capstan 42(14) andones up to the second capstan 42(15), it is possible to obtain thestrands 10 b having diameters of 0.42 mm, 0.36 mm, 0.34 mm and 0.32 mmto be manufactured.

That is, in the case of manufacturing the strand 10 b having a diameterof 0.30, as shown in FIG. 1 and FIG. 2, the wire 10 is wound around allof the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) andall of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and42(15). The dies 60 are disposed between ones among all of them, and thewires 10 are inserted through the all dies 60. In this state, then, therespective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8)and the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14)and 42(15) are rotated at rotational speeds so as to obtain the drawingspeed ratios corresponding to the above-mentioned percentages of areareduction. Any one of rotational speeds is determined, whereby each ofthe actual rotational speeds is determined based on the determined onein accordance with the above-mentioned drawing speed ratio. Generally, aspeed as high as possible is selected within the range where breaking ofthe wire 10 does not occur at a predetermined frequency or more on themost downstream side on which the wire speed becomes the highest. As aresult, the wire 10 is sequentially processed through compression anddeformation, whereby the strand 10 b having the smallest diameter of0.30 mm is manufactured.

For example, in the case of manufacturing a strand having a diameter of0.32 mm, as shown in FIG. 5, part of the second capstans 42(9), 42(10),. . . , 42(13), 42(14) and 42(15) and part of the dies 60 are omitted.More specifically, the wire 10 is caused to pass through without beingaround the second capstan 42(14). In addition, the die 60 disposedbetween the second capstans 42(14) and 42(15) is removed, and the die 60that has been disposed between the second capstans 42(13) and 42(14) isprovided in that location. Not the second capstan 42(15) on the mostdownstream side but the preceding second capstan 42(14) is omittedbecause a motor having relatively large torque is selected as afinishing capstan in the second capstan 42(15) on the most downstreamside.

Also in the case of manufacturing the strand 10 b having the otherdiameter of 0.42 mm, 0.36 mm or 0.34 mm, it can be manufactured in asimilar manner to the above by omitting one or a plurality of the secondcapstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15).

Accordingly, once the drawing speeds of a plurality of second capstans42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are set in accordancewith the material of the wire 10, a target diameter thereof or the like,it is possible to easily manufacture the strands 10 having a pluralityof types of finished wire diameters depending on whether all of or partof a plurality of second capstans 42(9), 42(10), . . . , 42(13), 42(14)and 42(15) is used.

Needless to say, the rotational speeds of the second capstans 42(9),42(10), . . . , 42(13), 42(14) and 42(15) may be changed or adjusted, orthe dies 60 may be replaced in accordance with a finished wire diameter.

According to the wire drawing machine 20 configured as described above,in the first capstan mechanism part 30, one first rotation drive source34 is transmitted to a plurality of first capstans 32(1), 32(2), . . . ,32(6), 32(7) and 32(8) via the first rotation transmission mechanismpart 36, with the result that maintenance tasks can be simplifiedcompared with the case of individually driving those by motors. Inaddition, in the second capstan mechanism part 40, the rotational speedsof a plurality of second rotation drive sources 44 are individuallyadjusted and the rotational speeds of the second capstans 42(9), 42(10),. . . , 42(13), 42(14) and 42(15) are individually changed, with theresult that the drawing speed ratio of the wire 10 can be changedbetween adjacent ones of the second capstans 42(9), 42(10), . . . ,42(13), 42(14) and 42(15). This enables an easy response to theadjustment or change of the degree of diameter reducing deformation ofthe wire 10 in accordance with the material of the wire 10, a targetfinished wire diameter or the like.

In the first capstan mechanism part 30, the percentage of area reductionis set to a relatively large fixed value, and thus the wire drawingprocess can be performed with efficiency in the stage where the wire 10has a relatively large diameter, resulting in a reduction of the numberof the whole dies 60. This contributes to reduction of a device size,cost or the like.

The drawing speed ratios between adjacent ones of the respective secondcapstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are set so asto gradually decrease toward the downstream, that is, as the diameter ofthe wire 10 becomes smaller. That is, setting is made such that thedegree of diameter reducing deformation by one die 60 becomes smaller asthe diameter of the wire 10 becomes smaller. This prevents cutting ofthe wire 10 more reliably.

FIG. 6 is a schematic plan view showing a wire drawing machine 120according to a modification. Similar components to those described inthe embodiment above are denoted by the same reference numerals anddescription thereof is omitted, and differences are mainly described.

In the present modification, description is given of an example in whicha finishing capstan located on the most downstream side is set to have afixed drawing speed. The wire drawing machine 120 includes the wiresupply part 22, the wire pulling part 26, a first capstan mechanism part130, a second capstan mechanism part 140, a finishing capstan mechanismpart 180 and the dies 60.

Similarly to the first capstan mechanism part 30, the first capstanmechanism part 130 is provided between the wire supply part 22 and thewire pulling part 26 on the side closer to the wire supply part 22 andincludes a plurality of (in this case, three) first capstans 132(1),132(2) and 132(3) corresponding to the first capstans 32(1), 32(2), . .. , 32(6), 32(7) and 32(8), a first rotation drive source 134corresponding to the first rotation drive source 34 and a first rotationtransmission mechanism part 136 corresponding to the first rotationtransmission mechanism part 36. That is, this first capstan mechanismpart 130 has a similar configuration to that of the first capstanmechanism part 30 except for a different number of first capstans132(1), 132(2) and 132(3) and a different number of rotation drive forcetransmission targets of the first rotation transmission mechanism part136.

Similarly to the second capstan mechanism part 40, the second capstanmechanism part 140 is provided between the wire supply part 22 and thewire pulling part 26 on the side closer to the wire pulling part 26 thanthe first capstan mechanism part 130 and includes a plurality of (inthis case, three) second capstans 142(4), 142(5) and 142(6)corresponding to the second capstans 42(9), 42(10), . . . , 42(13),42(14) and 42(15) and a plurality of (in this case, four) secondrotation drive sources 144 corresponding to the second rotation drivesources 44. That is, this second capstan mechanism part 140 has asimilar configuration to that of the second capstan mechanism part 40except for a different number of second capstans 142(4), 142(5) and142(6) and a different number of second rotation drive sources 144.

The finishing capstan mechanism part 180 serves to draw the wire 10 at aconstant drawing speed, is provided between the wire supply part 22 andthe wire pulling part 26 on the side closer to the wire pulling part 26than the second capstan mechanism part 140, and includes a plurality of(in this case, three) finishing capstans 182(7), 182(8) and 182(9), onefinishing rotation drive source 182, and a finishing transmissionmechanism part 184 that transmits the rotation drive force of thefinishing rotation drive source 182 to the plurality of finishingcapstans 182(7), 182(8) and 182(9). The plurality of (in this case,three) finishing capstans 182(7), 182(8) and 182(9) have similarconfigurations to those of the plurality of first capstans 132(1),132(2) and 132(3), one finishing rotation drive source 182 has a similarconfiguration to that of the first rotation drive source 134, and thefinishing transmission mechanism part 184 has a similar configuration tothat of the first rotation transmission mechanism part 136. Accordingly,the drawing speed ratios between ones of the finishing capstans 182(7),182(8) and 182(9) in the finishing capstan mechanism part 180 have fixedgiven values. Needless to say, the number of finishing capstans 182(7),182(8) and 182(9) does not need to be the same as the number of thefirst capstans 132(1), 132(2) and 132(3). Further, one drawing capstanmay be provided.

Further, the dies 60 are respectively disposed between ones of theplurality of first capstans 132(1), 132(2) and 132(3), the plurality ofsecond capstans 142(4), 142(5) and 142(6) and the plurality of finishingcapstans 182(7), 182(8) and 182(9).

This wire drawing machine 120 enables to perform the wire drawingprocess at a relatively large constant degree of diameter reducingdeformation by the first capstan mechanism part 130, perform the wiredrawing process at a degree of diameter reducing deformation that isadjusted in accordance with a material of the wire 10 or the like by thesecond capstan mechanism part 140, and perform the wire drawing processat a degree of diameter reducing deformation that is suitable forfinishing by the finishing capstan mechanism part 180. In particular,the finishing process can be performed on given conditions, leading to amerit of more stabilized finished quality.

While the description has been given by an example in which an aluminumwire or an aluminum alloy wire is assumed in the embodiment andmodification above, those are also applicable to the wires 10 of variousmaterials. That is, it suffices that the drawing speed ratios in thesecond capstan mechanism part 40, 140 are experimentally set or adjustedin accordance with the material of the wire 10, a process diameter orthe like.

While the description has been given assuming that the respectivecapstans have the same diameter, the respective diameters may differfrom each other. In this case, the drawing speed may be taken as a valueobtained by incorporating the diameter into the rotational speed.

Further, the case of a linear wire drawing process line L has been givenin the embodiment above, which is not limited thereto. Alternatively, aline may be curved at each capstan portion or other guide rollerportion.

While the wire drawing machine and the strand manufacturing method havebeen described in detail, the forgoing description is in all aspectsillustrative, and the present invention is not limited thereto. It istherefore understood that numerous modifications and variations notillustrated can be devised without departing from the scope of theinvention.

1. A wire drawing machine drawing a wire, comprising: a wire supply partsupplying a wire; a wire pulling part pulling the wire; a first capstanmechanism part provided between said wire supply part and said wirepulling part on a side closer to said wire supply part, which includes:a plurality of first capstans; a first rotation drive source; and afirst rotation transmission mechanism part transmitting a rotation driveforce of said first rotation drive source to said plurality of firstcapstans; a second capstan mechanism part provided between said wiresupply part and said wire pulling part on a side closer to said wirepulling part than said first capstan mechanism part, which includes: aplurality of second capstans; and a plurality of second rotation drivesources rotatively driving said plurality of second capstans in anindividual manner; and a plurality of dies disposed between ones of saidplurality of first capstans and said plurality of second capstans. 2.The wire drawing machine according to claim 1, wherein drawing speedratios between adjacent ones of said plurality of second capstans areset so that a wire that has passed through all of said plurality ofsecond capstans has a smallest finished wire diameter among a pluralityof types of finished wire diameters to be manufactured and that a wirethat has passed through part of said plurality of second capstans hasone finished wire diameter among the plurality of types of finished wirediameters to be manufactured.
 3. The wire drawing machine according toclaim 1, wherein drawing speed ratios between adjacent ones of saidplurality of second capstans are set so as to gradually decrease towardsaid wire pulling part.
 4. The wire drawing machine according to claim1, wherein: a wire subjected to a wire drawing process is an aluminumwire or an aluminum alloy wire; and drawing speed ratios between ones ofsaid plurality of first capstans are set so that the wire whose diameterhas been reduced to 0.5 mm or smaller is subjected to wire drawingprocess while the wire is drawn by said second capstan.
 5. The wiredrawing machine according to claim 1, further comprising a finishingcapstan mechanism part provided between said wire supply part and saidwire pulling part on a side closer to said wire pulling part than saidsecond capstan mechanism part, which includes: at least one finishingcapstan; a finishing rotation drive source; and a finishing transmissionmechanism part transmitting a rotation drive force of said finishingrotation drive source to said finishing capstan.
 6. A strandmanufacturing method of manufacturing a strand by drawing a wire with awire drawing machine including: a wire supply part supplying a wire; awire pulling part pulling the wire; a first capstan mechanism partprovided between said wire supply part and said wire pulling part on aside closer to said wire supply part, which includes: a plurality offirst capstans; a first rotation drive source; and a first rotationtransmission mechanism part transmitting a rotation drive force of saidfirst rotation drive source to said plurality of first capstans; asecond capstan mechanism part provided between said wire supply part andsaid wire pulling part on a side closer to said wire pulling part, whichincludes: a plurality of second capstans; and a plurality of secondrotation drive sources rotatively driving said plurality of secondcapstans in an individual manner; and a plurality of dies disposedbetween ones of said plurality of first capstans and said plurality ofsecond capstans, the method comprising: setting rotational speeds ofsaid plurality of second capstans so that a wire that has passed throughall of said plurality of second capstans has a smallest finished wirediameter among a plurality of types of finished wire diameters to bemanufactured and that a wire that has passed through part of saidplurality of second capstans has one finished wire diameter among theplurality of types of finished wire diameters to be manufactured; andchanging targets of said plurality of second capstans through which saidwire passes to all or part thereof, to thereby manufacture strandshaving the plurality of types of finished wire diameters.